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Context.-The clinical validity of mucin expression in gastric cancer is debated. Whereas several reports demonstrate a correlation between mucin expression and prognosis, others deny such an association.Objective.-This survival analysis study aims to elucidate the prognostic significance of mucin expression in gastric cancer.Design.-A retrospective survival analysis was done with 412 cases of gastric cancer characterized on the basis of MUC immunohistochemistry using MUC2, MUC5AC, MUC6, and CD10 antibodies; the cases were divided into those with a gastric, an intestinal, or a null mucin phenotype based on the predominant mucin.Results.-There was no association between mucin expression and survival when considering overall gastric cancers or the advanced gastric cancer subtype. However, early gastric cancers with a gastric mucin phenotype showed longer survival than those with an intestinal mucin phenotype (P ¼ .01) or a null phenotype (P ¼ .01). In particular, MUC5AC-positive early gastric cancers resulted in longer survival than did those that did not express MUC5AC (P ¼ .009). The loss of MUC5AC expression was identified as an independent, poor prognostic factor in early gastric cancers using the Cox regression proportional hazard model (hazard ratio, 3.50; P ¼ .045).Conclusions.-MUC5AC expression is significantly associated with patient survival and can be used to predict outcomes in the gastric cancers, especially in the early gastric cancers.

Actinobacillus pleuropneumoniae is the causative agent of porcine pleuropneumonia. Among the virulence factors of the pathogen, ApxIIA, a bacterial exotoxin, is expressed by many serotypes and presents a plausible target for vaccine development. We characterized the region within ApxIIA that induces a protective immune response against bacterial infection using mouse challenge model. Recombinant proteins spanning the length of ApxIIA were produced and antiserum to the full-length ApxIIA was induced in mice. This antiserum recognized fragments #2, #3 and #5 with high binding specificity, but showed poor recognition for fragments #1 and #4. Of the antisera induced in mice by injection of each fragments, only the antiserum to fragment #4 failed to efficiently recognize the full-length antigen, although the individual antisera recognized their cognate antigens with almost equal efficiency. The protective potency of the immunogenic proteins against a challenge injection of bacteria in vivo correlated well with the antibody titer. Fragment #5 induced the highest level of protective activity, comparable to that by the full-length protein. These results support the use of fragment #5 to produce a vaccine against A. pleuropneumoniae challenge, since the small antigen peptide is easier to handle than is the full-length protein and can be expressed efficiently in heterologous expression systems.